Dover Wilden Original PV20, Инженерия, эксплуатация и обслуживание, Страница: 11 / 25

TT5049 EOM-PV20M 9/05
9
WILDEN PUMP & ENGINEERING, LLC
OPERATION: The Pro-Flo ® and Pro-Flo V™ pumps are
pre-lubricated, and do not require in-line lubrication.
Additional lubrication will not damage the pump,
however if the pump is heavily lubricated by an
external source, the pump’s internal lubrication may
be washed away. If the pump is then moved to a non-
lubricated location, it may need to be disassembled
and re-lubricated as described in the ASSEMBLY/
DISASSEMBLY INSTRUCTIONS.
Pump discharge rate can be controlled by limiting the
volume and/or pressure of the air supply to the pump. A
regulator is used to control air pressure while a needle
valve is used to control volume. Pump discharge rate
can also be controlled by throttling the pump discharge
by partially closing a valve in the discharge line of the
pump. This action increases friction loss which reduces
fl ow rate. (See Section 5.) This is useful when the need
exists to control the pump from a remote location.
When the pump discharge pressure equals or exceeds
the air supply pressure, the pump will stop; no bypass
or pressure relief valve is needed, and pump damage
will not occur. The pump has reached a “deadhead”
situation and can be restarted by reducing the fl uid
discharge pressure or increasing the air inlet pressure.
The Pro-Flo
®
and Pro-Flo V™ pumps run solely on
compressed air and do not generate heat, therefore
your process fl uid temperature will not be affected.
MAINTENANCE AND INSPECTIONS: Since each
application is unique, maintenance schedules may be
different for every pump. Frequency of use, line pressure,
viscosity and abrasiveness of process fl uid all affect
the parts life of a Wilden pump. Periodic inspections
have been found to offer the best means for preventing
unscheduled pump downtime. Personnel familiar with
the pump’s construction and service should be informed
of any abnormalities that are detected during operation.
RECORDS: When service is required, a record should be
made of all necessary repairs and replacements. Over
a period of time, such records can become a valuable
tool for predicting and preventing future maintenance
problems and unscheduled downtime. In addition,
accurate records make it possible to identify pumps
that are poorly suited to their applications.
Pump will not run or runs slowly.
1. Ensure that the air inlet pressure is at least 0.3 Bar
(5 psig) above startup pressure and that the differential
pressure (the difference between air inlet and liquid
discharge pressures) is not less than 0.7 Bar (10 psig).
2. Check air inlet fi lter for debris (see recommended
installation).
3. Check for extreme air leakage (blow by) which
would indicate worn seals/bores in the air valve,
pilot spool, main shaft.
4. Disassemble pump and check for obstructions
in the air passageways or objects which would
obstruct the movement of internal parts.
5. Check for sticking ball check valves. If material being
pumped is not compatible with pump elastomers,
swelling may occur. Replace ball check valves and
seals with proper elastomers. Also, as the check
valve balls wear out, they become smaller and can
become stuck in the seats. In this case, replace balls
and seats.
6. Check for broken inner piston which will cause the
air valve spool to be unable to shift.
7. Remove plug from pilot spool exhaust.
Pump runs but little or no product fl ows.
1. Check for pump cavitation; slow pump speed down
to allow thick material to fl ow into liquid chambers.
2. Verify that vacuum required to lift liquid is not
greater than the vapor pressure of the material
being pumped (cavitation).
3. Check for sticking ball check valves. If material being
pumped is not compatible with pump elastomers,
swelling may occur. Replace ball check valves and
seats with proper elastomers. Also, as the check
valve balls wear out, they become smaller and can
become stuck in the seats. In this case, replace balls
and seats.
Pump air valve freezes.
1. Check for excessive moisture in compressed
air. Either install a dryer or hot air generator for
compressed air. Alternatively, a coalescing fi lter may
be used to remove the water from the compressed
air in some applications.
Air bubbles in pump discharge.
1. Check for ruptured diaphragm.
2. Check tightness of outer pistons (refer to Section 7).
3. Check tightness of fasteners and integrity of
o-rings and seals, especially at intake manifold.
4. Ensure pipe connections are airtight.
Product comes out air exhaust.
1. Check for diaphragm rupture.
2. Check tightness of outer pistons to shaft.
T R O U B L E S H O O T I N G